Sigh...
Despite what I had believed to be accurate measuring, sewing and cutting, I clearly did something wrong because my lone-star diamonds are not "right". Now I have eight worthless 6x6 diamonds and I don't know what to do with them. I am horrified that I've done all this work and that I didn't catch the problem right away. I mean the diamonds are catty-wampus. Any suggestions for what to do with these, other than cremate them?

since you;ve got so many bias edges you could try starching and sizing the diamonds to shape by pinning them to a board for drying..draw out the shape they should be then pin to that size after they're wet with starch and let dry...

Or, separate each of the dimonds and applique them to a solid background and add sashing, etc to enlarge the star design and hide the discrepancies in size...your own design.

It looks to me that they are all stretched in the same way. When sewing did you alternate the direction in which you sewed? Ive not done a lonestar but I know in other strip piecing sometimes if you sew the other way it helps. I think i would try ktbb's suggestion.

Have you tried to reposition them? That might help. In the photo it looks like some of them that aren't next to each other might fit better with another one. Not sure if that makes sense. Move them around . . .

1943, I did try that. As you may be able to tell from the photo, I took a big piece of butcher paper and drew out the lines into which the diamonds should have fit. I rearranged them every which way and always had at least two that wouldn't fit.

I'm now wondering if I did something wrong from the very beginning-- like when I cut the diagonal strips (from the horizontal) that I cut them too wide.

Mmm... maybe there's a solution there? undo each of the strips and re-measure *those*; when stitched together, shouldn't each of the individual diamonds be "perfect" diamonds, not as "stretched" as they currently are?

They should be diamonds. I haven't done one for so long and back then we cut each piece by hand. Maybe you want to try the starching or just dampen then and try to block them all to one sizie/shape. It's a shame not to use them. The colors are so pretty.